模拟失重对流体剪切应力致大鼠颅骨成骨细胞PGE_2 分泌的影响(英文)

Effects of Simulated Weightlessness on the Release of PGE_2 in Rat Calvarial Osteoblasts Induced by Flow Shear Stress

目的为探讨失重环境对骨骼细胞的力学信号转导功能的影响 ,细胞这种功能的变化在失重性骨质稀少中的作用 ,以及空间飞行锻炼效果不良与之的关系。观察了模拟失重对流体剪切应力致大鼠成骨细胞PGE2 分泌的影响。方法传代培养的大鼠乳鼠颅骨成骨细胞分为两组 ,一组在地面重力环境下培养 ,另一组则置于回转器中培养 60h。然后 ,将成骨细胞置于流体槽中给予 0 .5Pa或 1 .5Pa的流体剪切应力作用 1h ,检测细胞分泌前列腺素E2 的变化。结果在 1G重力环境下培养的成骨细胞中 ,在一定的时间范围内 ( 560min) ,细胞PGE2 的分泌反应随剪切应力作用时间的延长而显著增强 (P <0 .0 1 ) ;而在一定的剪切应力范围内 ( 0 .51 .5Pa) ,细胞PGE2 的分泌反应与应力水平无明显关系 ,即不随剪切应力的大小而改变 (P >0 .0 5)。与之相比 ,模拟失重环境下培养的成骨细胞对剪切应力的反应性下降 ,即 0 .5Pa应力作用下无PGE2 的分泌反应 (P <0 .0 1 ) ,1 .5Pa应力作用下PGE2 的分泌延缓并且分泌水平下降 (P <0 .0 1 )。

Objective To observe the effects of simulated weightlessness on the release of prostaglandin E 2 in rat calvarial osteoblasts by flow shear stress (FSS). Method Osteoblasts were isolated from neonatal rat calvariae and then were set to two groups. One was cultured in 1G terrestrial gravitational environment. The other was cultured on a clinostat (simulating weightlessness environment) for 60 h, then the osteoblasts were treated with 0.5 Pa or 1.5 Pa FSS in a flow chamber for 1 h. Then release of PGE 2 in the osteoblasts was determined. Result 0.5 Pa and 1.5 Pa FSS treatments significantly increased the release of PGE 2 in osteoblasts cultured in 1G environment (P<0.01), but there was no remarkable difference between the responses of 0.5 Pa FSS treatment group and 1.5 Pa group (P>0.05). By contrast, in cells cultured in simulated weightlessness environment, no detectable release of PGE 2 was found with the treatment of 0.5 Pa FSS (P<0.01). The release of PGE 2 was delayed and the amount of PGE 2 production was remarkably decreased with 1.5 Pa FSS treatment (P<0.01). Conclusion These results demonstrated that the responsiveness of osteoblasts to FSS was down regulated in simulated weightlessness.